OpenStreetMap Tagging Schema MCP Server (io.github.gander-tools/osm-tagging-schema-mcp)

MCP server for querying and validating OpenStreetMap (OSM) tags. It is built to work with an OSM tagging schema and focuses on validation workflows involving OSM tag data. The repository is associated with TypeScript tooling and includes automated CI/CD checks and fuzzing.

🛠️ Key Features

Query OSM tags
Validate OSM tags against a tagging schema
TypeScript-based implementation
Tagged for validation and tagging-schema use

🚀 Use Cases

Checking whether OSM tags conform to a schema
Supporting AI tooling workflows that process OSM tag data
Integrating OSM tag validation into development pipelines

⚡ Developer Benefits

Developer-oriented: MCP server for OSM tag querying/validation
Topics indicate support for “validation” and “osm-tags”
CI and fuzzing workflows available in the repository

⚠️ Limitations

Public details provided here do not specify available tools, schemas, or exact validation rules

OpenStreetMap Tagging Schema MCP Server

What is this?

This is a Model Context Protocol (MCP) server designed specifically for AI agents and LLM applications. It acts as a bridge between artificial intelligence systems and the comprehensive OpenStreetMap tagging knowledge base provided by the official @openstreetmap/id-tagging-schema library.

Project status

This project is a Proof of Concept. It gives real value in some areas and has known gaps in others, both described honestly below.

It works with the latest tagging schema, @openstreetmap/id-tagging-schema v7.
A better replacement tool is being worked on. It will arrive later than originally planned, and no date is promised.

Bug reports and ideas: open an issue or start a discussion.

How it works

The server runs over stdio (default) or HTTP and exposes the tagging schema as MCP tools. Every tool reads the schema data shipped in @openstreetmap/id-tagging-schema (presets, fields, deprecated tags, translations) and answers from it deterministically. There is no network access to OSM and no AI inside the server: the AI agent calls the tools and interprets the results.

Validation checks a tag against the schema: known key, value allowed by the matching field, deprecated key/value with a suggested replacement.

What works and what doesn't

The tool has limitations. Know what to expect before relying on it: it answers from the schema data only, and a part of the tags that exist in the wild or on the OSM wiki is not covered.

Tool	Works	Limitations
`validate_tag`	Popular tags accepted (100%), almost no false `deprecated` alarms (99.2%)	Detects only ~20% of wiki-deprecated tags; typos and foreign values are accepted as valid (custom tags are allowed); `railway=platform` and `railway=station` are wrongly flagged as deprecated
`validate_tag_collection`	Consistent with `validate_tag` (100%)	Same gaps as `validate_tag`; control characters are not reported
`suggest_improvements`	Preset matched for 92% of popular tags	Typos and foreign values usually yield suggestions, not a problem report
`get_tag_values`	97% of taginfo values present; bad keys and limits rejected	A few taginfo values are missing from the lists
`search_tags`	Finds 60% of keys by name	No typo tolerance despite the fuzzy-matching description; keys with a colon (`addr:street`) are often missed; `limit` of 0 or negative not always rejected; `access` returns a `keyMatches` item without `key`
`search_presets`	Preset found for 69% of popular tags (56% in top 3)	Multi-word queries (`bicycle parking`) can return nothing; weak ranking; `limit` of 0 or negative not always rejected
`get_preset_details`	Preset exists for 93% of popular tags; unknown ids always rejected	Some popular tags (e.g. `historic=*`, `craft=grinding_mill`, `railway=stop`) have no preset
`compare_tags`	Matches local computation (100%); text and JSON input give identical output	Compares any tag sets, so it never says a tag is wrong; only malformed input is rejected
`flat_to_json`	Lossless, including `;`, spaces, `=`, Unicode, `:` and `/`	Duplicate keys and control characters are accepted silently
`json_to_flat`	Lossless round-trip (100%); bad input rejected	Keys are not sorted alphabetically, input order is kept

Across all tools, invalid input never crashed the server: errors are readable or the result is an empty list.

Summary

Useful where deterministic logic is enough: format conversion, comparing tag sets, reading presets and values, validating popular tags. Weakest areas: deprecated tag detection and search (typos, multiple words, colon keys).

What this is NOT

⚠️ Important clarifications:

Not a standalone application: This server requires integration with AI systems (like Claude Code or Claude Desktop) to be useful. It has no user interface or web frontend.
Not for direct human use: Without an AI agent as an intermediary, this tool provides no value to end users. It's designed exclusively for programmatic access by LLM applications.

If you're looking for a user-facing OSM tagging tool, consider iD editor or JOSM instead.

Installation

Add the server to Claude Code (stdio):

bash

# npx
claude mcp add --transport stdio osm-tagging-schema -- npx -y @gander-tools/osm-tagging-schema-mcp

# Docker
claude mcp add --transport stdio osm-tagging-schema -- docker run -i --rm ghcr.io/gander-tools/osm-tagging-schema-mcp:latest

HTTP transport

stdio is the default. Set TRANSPORT=http to serve over HTTP (streamable, port 3000 in the Docker image):

Variable	Default	Meaning
`TRANSPORT`	`stdio`	`stdio` or `http`
`PORT`	`3000`	HTTP port
`HOST`	`0.0.0.0`	HTTP bind address
`CORS_ORIGINS`	`http://localhost:6274,https://mcp.ziziyi.com`	Comma-separated allowed CORS origins
`LOG_LEVEL`	`INFO`	`SILENT`, `ERROR`, `WARN`, `INFO`, `DEBUG`

bash

docker run --rm -p 3000:3000 -e TRANSPORT=http ghcr.io/gander-tools/osm-tagging-schema-mcp:latest

Endpoints: GET /health (liveness), GET /ready (schema loaded), GET /version.

License

GNU General Public License v3.0 - See LICENSE file for details.